/*
 * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * The Universal Permissive License (UPL), Version 1.0
 *
 * Subject to the condition set forth below, permission is hereby granted to any
 * person obtaining a copy of this software, associated documentation and/or
 * data (collectively the "Software"), free of charge and under any and all
 * copyright rights in the Software, and any and all patent rights owned or
 * freely licensable by each licensor hereunder covering either (i) the
 * unmodified Software as contributed to or provided by such licensor, or (ii)
 * the Larger Works (as defined below), to deal in both
 *
 * (a) the Software, and
 *
 * (b) any piece of software and/or hardware listed in the lrgrwrks.txt file if
 * one is included with the Software each a "Larger Work" to which the Software
 * is contributed by such licensors),
 *
 * without restriction, including without limitation the rights to copy, create
 * derivative works of, display, perform, and distribute the Software and make,
 * use, sell, offer for sale, import, export, have made, and have sold the
 * Software and the Larger Work(s), and to sublicense the foregoing rights on
 * either these or other terms.
 *
 * This license is subject to the following condition:
 *
 * The above copyright notice and either this complete permission notice or at a
 * minimum a reference to the UPL must be included in all copies or substantial
 * portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package com.oracle.truffle.polyglot;

import java.lang.reflect.Proxy;
import java.util.Objects;

import com.oracle.truffle.api.CompilerDirectives.TruffleBoundary;

interface HostWrapper {

    Object getGuestObject();

    PolyglotContextImpl getContext();

    PolyglotLanguageContext getLanguageContext();

    static boolean isInstance(Object v) {
        if (v == null) {
            return false;
        } else if (v instanceof Proxy) {
            return isHostProxy(v);
        } else {
            return v instanceof HostWrapper;
        }
    }

    @TruffleBoundary
    static boolean isHostProxy(Object v) {
        if (Proxy.isProxyClass(v.getClass())) {
            return Proxy.getInvocationHandler(v) instanceof HostWrapper;
        } else {
            return false;
        }
    }

    static HostWrapper asInstance(Object v) {
        if (v instanceof Proxy) {
            return getHostProxy(v);
        } else {
            return (HostWrapper) v;
        }
    }

    @TruffleBoundary
    static HostWrapper getHostProxy(Object v) {
        return (HostWrapper) Proxy.getInvocationHandler(v);
    }

    static boolean equals(HostWrapper wrapper, Object other) {
        if (other == null) {
            return false;
        } else if (wrapper == other) {
            return true;
        } else if (wrapper.getClass() == other.getClass()) {
            PolyglotContextImpl thisContext = wrapper.getContext();
            Object thisGuestObject = wrapper.getGuestObject();
            PolyglotContextImpl otherContext = ((HostWrapper) other).getContext();
            Object otherGuestObject = ((HostWrapper) other).getGuestObject();
            return thisContext == otherContext && Objects.equals(thisGuestObject, otherGuestObject);
        } else {
            return false;
        }
    }

    static boolean equalsProxy(HostWrapper wrapper, Object other) {
        if (other == null) {
            return false;
        } else if (Proxy.isProxyClass(other.getClass())) {
            return equals(wrapper, Proxy.getInvocationHandler(other));
        } else {
            return false;
        }
    }

    static int hashCode(HostWrapper thisObj) {
        return thisObj.getGuestObject().hashCode();
    }

    static String toString(HostWrapper thisObj) {
        PolyglotLanguageContext thisContext = thisObj.getLanguageContext();
        Object thisGuestObject = thisObj.getGuestObject();
        if (thisContext != null) {
            try {
                return thisContext.asValue(thisGuestObject).toString();
            } catch (Exception e) {
            }
        }
        return "Error in toString()";
    }

}
